1. Field of the Invention
The present invention relates to a method for controlling a dead time of a secondary side of a power converter, and particularly to a method that can ensure that a primary side and a secondary side of an alternating current (AC)/direct current (DC) power converter are not simultaneously turned on when a frequency of a control signal of a power switch of the primary side of the AC/DC power converter is suddenly changed.
2. Description of the Prior Art
Generally speaking, conversion efficiency of a switching alternating AC/DC power converter is better than conversion efficiency of a non-switching AC/DC power converter, but a primary side and a secondary side of the switching AC/DC power converter can not be simultaneously turned on to prevent the switching AC/DC power converter from being burned. When a frequency of a control signal of a power switch of the primary side of the switching AC/DC power converter is not suddenly changed, the primary side and the secondary side of the switching AC/DC power converter are not simultaneously turned on. However, if the frequency of the control signal of the power switch of the primary side of the switching AC/DC power converter is suddenly changed, the primary side and the secondary side of the switching AC/DC power converter may be simultaneously turned on, resulting in the switching AC/DC power converter being burned. Therefore, how to ensure that the primary side and the secondary side of the switching AC/DC power converter are not simultaneously turned on when the switching AC/DC power converter operates has become an important issue of a designer of a synchronous rectifier applied to the secondary side of the switching AC/DC power.